Method of manufacturing an electro-active lens

ABSTRACT

A method of manufacturing an electro-active lens is disclosed. The lens is manufactured by providing a lens blank having a front and back surface, a thickness, and an index of refraction. An electro-active element is placed on one of the front or back surfaces of the lens blank. A covering surface is then formed over the surface of the lens blank containing the electro-active element. In some embodiments, the electro-active lens may then be surfaced to provide a desired fixed optical power and edged to fit within a spectacles frame.

This application claims the benefit of U.S. Provisional Application No.60/404,657 filed Aug. 20, 2002. This application is also acontinuation-in-part of U.S. patent application Ser. No. 10/422,128filed Apr. 24, 2003, which claims the benefit of U.S. ProvisionalApplication No. 60/375,028, filed Apr. 25, 2002, and which is acontinuation-in-part of U.S. patent application Ser. No. 10/387,143,filed Mar. 12, 2003, which claims the benefit of U.S. ProvisionalApplication Nos. 60/363,549, filed Mar. 13, 2002 and 60/401,700, filedAug. 7, 2002, and which is a continuation-in-part of U.S. patentapplication Ser. No. 10/263,707 filed Oct. 4, 2002, Ser. No.10/281,204,filed Oct. 28, 2002 and Ser. No. 10/046,244, filed Jan. 16, 2002. U.S.patent application Ser. No. 10/263,707 claims the benefit of U.S.Provisional Application Nos. 60/331,419, filed Nov. 15, 2001, and60/326,991, filed Oct. 5, 2001. U.S. patent application Ser. No.10/281,204 is a continuation of U.S. Pat. No. 6,491,394, filed Jun. 23,2000. U.S. patent application Ser. No. 10/046,244 claims the benefit ofU.S. Provisional Application Nos. 60/261,805, filed Jan. 17, 2001,60/331,419, filed Nov. 15, 2001, and 60/326,991, filed Oct. 5, 2001, andis a continuation-in-part of U.S. Pat. No. 6,491,391, filed Jun. 23,2000, U.S. Pat. No. 6,491,394, filed Jun. 23, 2000, and U.S. Pat. No.6,517,203, filed Jun. 23, 2000, and U.S. patent application Ser. No.09/602,013, filed Jun. 23, 2000; all of which claim priority to U.S.Provisional Application Nos. 60/142,053, filed Jul. 2, 1999, 60/143,626,filed Jul. 14, 1999, 60/147,813, filed Aug. 10, 1999, 60/150,545, filedAug. 25, 1999, 60/150,564, filed Aug. 25, 1999, and 60/161,363, filedOct. 26, 1999. All of the foregoing applications, provisionalapplications, and patents are herein incorporated by reference in theirentirety.

FIELD OF THE INVENTION

The present invention relates to an efficient method of manufacturing anelectro-active lens.

SUMMARY OF THE INVENTION

In an exemplary embodiment of the invention, a method of manufacturingan electro-active lens from a lens blank is disclosed. The lens blankcomprises a front surface, a back surface, a thickness and an index ofrefraction. An electro-active element may be placed on either the frontor back surface of the lens blank. The method further comprises forminga covering layer over the surface of the lens blank containing theelectro-active element.

In another exemplary embodiment, another method of manufacturing anelectro-active lens is disclosed. The method comprises molding a lensblank having a front surface, a back surface, a thickness and an indexof refraction around an electro-active element.

Aspects of the present invention will now be described in more detailwith reference to exemplary embodiments thereof as shown in the appendeddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a method of manufacturing an electro-activelens according to an exemplary embodiment of the invention.

FIG. 2 is a flow chart of a method of manufacturing an electro-activelens according to an exemplary embodiment of the invention.

FIGS. 2A-2F illustrate a lens at various stages in the method shown inFIG. 2.

FIG. 3 illustrates a top view of a semi-finished fly-away mold gasketaccording to an exemplary embodiment of the invention.

FIG. 4 illustrates a cross-section of the semi-finished fly-away moldgasket of FIG. 3.

FIG. 5 is a flow chart of a method of manufacturing an electro-activelens according to another exemplary embodiment of the invention.

FIGS. 5A-5F illustrate a lens at various stages in the method shown inFIG. 5.

FIG. 6 is a flow chart of a method of manufacturing an electro-activelens according to yet another exemplary embodiment of the invention.

FIGS. 6A-6E illustrate a lens at various stages in the method shown inFIG. 6.

FIG. 7 is a flow chart of a method of manufacturing an electro-activelens according to an exemplary embodiment of the invention.

FIGS. 7A illustrate an electro-active lens manufactured by the methoddescribed in FIG. 7.

FIGS. 8A-8C illustrate conductive bus arrangements according toalternative embodiments of the invention.

FIG. 9A-9C illustrate an exemplary embodiment of an electro-active lenshaving conductive bus arrangements.

FIG. 10A illustrates a rear view of a spectacles frame having anelectro-active lens manufactured according to an exemplary embodiment ofthe invention.

FIG. 10B illustrates a top view of a spectacles frame having anelectro-active lens manufactured according to an exemplary embodiment ofthe invention.

FIGS. 11A and 11B illustrate an alternative embodiment of the spectaclesframe of FIGS. 10A and 10B having an electro-active lens manufactureaccording to an exemplary embodiment of the invention.

FIGS. 12A and 12B illustrate an alternative embodiment of the spectaclesframe of FIGS. 10A and 10B having an electro-active lens manufactureaccording to an exemplary embodiment of the invention.

FIG. 13A-13D illustrate a battery attachment mounted on or near a framehinge according to an exemplary embodiment of the invention.

FIG. 14 illustrates integrated electrical components for use inmanufacturing an electro-active lens according to an exemplaryembodiment of the invention.

FIG. 15 illustrates another embodiment of integrated electricalcomponents for use in manufacturing an electro-active lens according toan exemplary embodiment of the invention.

FIG. 16 is a flow chart of a method of finishing and mounting integratedelectronic components in manufacturing an electro-active lens accordingto still another exemplary embodiment of the invention.

FIGS. 16A-16E illustrate a lens at various stages in the method shown inFIG. 16.

FIG. 17 is a flow chart of a method of finishing a lens with electroniccomponents in manufacturing an electro-active lens according to anotherexemplary embodiment of the invention.

FIGS. 17A-17E illustrate a lens at various stages in the method shown inFIG. 17.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In 1998, there were approximately 92 million eye examinations performedin the United States alone. The vast majority of these examinationsinvolved a thorough check for eye pathology both internal and external,analysis of muscle balance and binocularity, measurement of the corneaand, in many cases, the pupil, and finally a refractive examination,which was both objective and subjective.

Refractive examinations are performed to understand/diagnose themagnitude and type of the refractive error of one's eye. The types ofrefractive error that are currently able to be diagnosed & measured, aremyopia, hyperopia, astigmatism, and presbyopia. Current refractors(phoropters) attempt to correct one's vision to 20/20 distance and nearvision. In some cases, 20/15 distance vision can be achieved; however,this is by far the exception.

It should be pointed out that the theoretical limit to which the retinaof one's eye can process and define vision is approximately 20/08. Thisis far better than the level of vision which is currently obtained byway of both today's refractors (phoropters) and conventional spectaclelenses. What is missing from these conventional devices is the abilityto correct for non-conventional refractive error, such as aberrations,irregular astigmatism, or ocular layer irregularities. Theseaberrations, irregular. astigmatism, and/or ocular layer irregularitiesmay be a result of one's visual system or a result of aberrations causedby conventional eyeglasses, or a combination of both.

In accordance with exemplary embodiments of the invention, methods ofmanufacturing an electro-active lens are disclosed. The electro-activelens may be used to provide vision correction for one or more focallengths, and may further correct non-conventional refractive errorincluding higher order aberrations.

To assist with understanding certain embodiments of the invention,explanations of various terms are now provided. “Attaching” can includebonding, depositing, adhering, and other well-known attachment methods.A “controller” can include or be included in a processor, amicroprocessor, an integrated circuit, a computer chip, and/or a chip. A“conductive bus” operates to conduct data in the form of an electricalsignal from one place to another place. “Near distance refractive error”can include presbyopia and any other refractive error needed to becorrected for one to see clearly at near distance. “Intermediatedistance refractive error” can include the degree of presbyopia neededto be corrected an intermediate distance and any other refractive errorneeded to be corrected for one to see clearly at intermediate distance.“Far distance refractive error” can include any refractive error neededto be corrected for one to see clearly at far distance. “Conventionalrefractive error” can include myopia, hyperopia, astigmatism, and/orpresbyopia. “Non-conventional refractive error” can include irregularastigmatism, aberrations of the ocular system including coma, chromaticaberrations, and spherical aberrations, as well as any other higherorder aberrations or refractive error not included in conventionalrefractive error. “Optical refractive error” can include any aberrationsassociated with a lens optic.

In certain embodiments, a “spectacle” can include one lens. In otherembodiments, a “spectacle” can include more than one lens. A“multi-focal” lens can include bifocal, trifocal, quadrafocal, and/orprogressive addition lens. A “finished” lens blank can include a lensblank that has a finished optical surface on both sides. A“semi-finished” lens blank can include a lens blank that has, on oneside only, a finished optical surface, and on the other side, anon-optically finished surface, the lens needing further modifications,such as, for example, grinding and/or polishing, to make it into auseable lens. An “unfinished” lens blank has no finished surface oneither side. “Base lens” refers to the non-electro-active portion of alens blank which has been finished.

“Surfacing” can include grinding and/or polishing off excess material tofinish a non-finished surface of a semi-finished or unfinished lensblank. The lens blank may also be finished using free form machiningtechniques that have recently been adopted by the ophthalmic lensindustry. Free forming techniques allow a completely arbitrary shape tobe placed on the lens blank that may be used to complete conventionalerror correction, but may also be used to correct higher orderaberrations to provide for a non-conventional error correction that maylead to vision correction better than 20/20. Further, the lens blank canbe fabricated by bonding two or more lens wafers together to form afinished lens or a semi-finished lens blank. It should be appreciatedthat the lens blank, whether finished, unfinished, or semi-finished, mayinitially be fabricated using free form techniques to correct for eitheror both of conventional and non-conventional refractive error.

A method of manufacturing an electro-active lens is disclosed as shownin FIG. 1. The method comprises providing a lens blank as shown in step10. The lens blank may be any type of lens blank and has a front andback surface, a thickness, and an index of refraction. In step 20, anelectro-active element is placed on either the front or back surface ofthe lens blank. In step 30, a covering layer is formed over the surfaceof the lens blank containing the electro-active element. This coveringlayer protects the electro-active element and fixes the electro-activeelement at a location on the lens blank. The material used to create thecovering layer may also, in combination with the lens blank, provide afixed distance vision correction to a wearer of the lens.

The electro-active element may comprise one or more layers ofelectro-active material, such as a polymer gel and/or liquid crystalswhich, when activated by an applied electrical voltage, produce an indexof refraction which is variable with the amount of the electricalvoltage applied to the electro-active material. When a wearer viewsthrough an area of the electro-active lens containing the electro-activeelement, the wearer may achieve vision correction based on the index ofrefraction of the electro-active element, which may be in addition tovision correction provided by the non-electro-active portion of thelens. Suitable electro-active materials include various classes ofliquid crystals and polymer gels. These classes include nematic,smectic, and cholesteric liquid crystals, polymer liquid crystals,polymer dispersed liquid crystals, and polymer stabilized liquidcrystals as well as electro-optic polymers.

If liquid crystals such as nematic liquid crystals are used as theelectro-active material, an alignment layer may be required becausenematic and many other liquid crystals, are birefringent. That is, theydisplay two different focal lengths when exposed to unpolarized lightabsent an applied voltage. This birefringence gives rise to double orfuzzy images on the retina. To alleviate this birefringence, a secondlayer of electro-active material may be used, aligned orthogonal to thefirst layer of electro-active material. In this manner, bothpolarizations of light are focused equally by both of the layers, andall light is focused at the same focal length.

Alternatively, the use of cholesteric liquid crystals, which have alarge chiral component, may be used instead as a preferredelectro-active material. Unlike nematic and other common liquidcrystals, cholesteric liquid crystals do not have the polarity ofnematic liquid crystals, avoiding the need for multiple layers ofelectro-active material.

Various electro-active layers which may be used in the electro-activeelement of embodiments of the present invention are described in theaforementioned applications which have previously been incorporated byreference in their entirety.

The lens blank may be any type of lens blank and may include, forexample, a semi-finished blank, an unfinished lens blank, a lens wafer,a preformed optic or a finished lens. The covering layer may be formedby conformal sealing such as by molding or surface-casting, or bycovering the lens blank with a lens wafer.

In an exemplary embodiment of the invention, an electro-active lens ismanufactured from a semi-finished blank, with a covering layer formed byconformal sealing. An electro-active element may be placed on either thefront or back surface of the semi-finished blank. The conformal sealforms a protective covering layer over the surface of the lens blank onwhich the electro-active element was placed, burying the electro-activeelement within the lens. FIG. 2 is a flow chart which illustrates amethod of manufacturing the electro-active lens using conformally sealedsemi-finished blanks according to an embodiment of the invention. FIGS.2A-E illustrate the lens at various stages of the method illustrated inFIG. 2. At step 100, a semi-finished blank 230, having a back concavesurface 202 and a front convex surface 204, may be selected, as shown inFIG. 2A. At step 110, a recess 205 may be cut in the front convexsurface 204 of the semi-finished blank 230, as shown in FIG. 2B. At step120, an electro-active element 200 may be placed in the recess 205.Additionally, a conductive bus 210 connected to the electro-activeelement 200 may be placed in the recess 205. Preferably, the conductivebus 210 may be constructed of an optically transparent, flexiblematerial, such as an extruded or cast polymer film of ophthalmic gradematerial which has been coated with a transparent conducting materialsuch as indium-tin-oxide and/or conductive polymers. The conductive bus210 may have a plurality of apertures, which may promote better bondingof the conductive bus to the lens blank 230.

At step 130, the electro-active element 200 and the conductive bus 210can be conformally sealed into the semi-finished blank 230, as shown inFIG. 2D, using a mold 220 containing a sealant, such as an opticallyclear resin, which preferably has an index of refraction near or equalto the index of refraction of the lens blank.

The electro-active element 200 and the conductive bus 210 is placed inthe mold 220 and capped with the lens blank 230. The resin may be curedby way of example only, by thermal energy, light energy, or acombination of the two. Light sources may include any one of or acombination of visible, ultraviolet or infrared sources.

At step 140, the semi-finished blank 230 can be demolded as shown inFIG. 2E to provide a semi-finished electro-active lens blank 235. Thecured resin creates a covering layer 215 over the front convex surface204, which has the effect of burying the electro-active element 200 andconductive bus 210 within the electro-active lens. The electro-activelens blank 235 has a covering surface 208 having a radius of curvatureequal to that of the mold 220. The radius of curvature of the coveringsurface 208 in combination with the radius of curvature of the backconcave surface 202 provides the fixed optical power.

A hard, scratch-resistant coating may optionally be applied to the lensas shown in step 150. Hard coating may be accomplished by dipping orspin coating the lens prior to finishing the semi-finishedelectro-active lens blank 235. It should be appreciated that the hardcoating may be applied to an inner surface of mold 220 before fillingthe mold with resin and curing the resin to the front convex surface 204of the lens blank, such that when the resin has cured and the coveringlayer is formed, the hard coat is already on the covering surface 208.

At step 160, the semi-finished electro-active lens blank 235 can befinished to a desired prescription, as shown in FIG. 2F, by surfacingthe electro-active lens blank 235 by known techniques to produce anelectro-active lens 240. The electro-active lens 240 may subsequently beedged to fit in a spectacles frame.

It should be appreciated that the front convex surface 204 and backconcave surface 202 of the lens blank 230 may have any or no degree ofcurvature, which may later be applied through various surfacingtechniques. Once the lens blank 230 has been conformally sealed to burythe electro-active element 200 and conductive bus 210, the final degreeof curvature imparted to back concave surface 202 and the coveringsurface 208 after finishing, not the front convex surface 204,determines the optical characteristics of the electro-active lens 240.

In an exemplary embodiment of the invention, the manufacturing of theelectro-active lens uses a preformed optic such as, but not limited to afinished, or single vision lens, for example. FIG. 6 illustrates amethod of manufacturing an electro-active lens from a lens blank whichis a single vision lens using a conformal sealing approach similar tothat described above in relation to FIG. 2 to create a covering layer tocontain the electro-active element within the lens. However, unlike thesemi-finished blank described with respect to the method in FIG. 2, asingle vision lens already has a prescription and does not need furthersurfacing to provide the correct fixed optical power to a wearer of thelens. Accordingly, in this embodiment, the conformal sealing ispreferably done in such a manner as to not change the power of theoriginal finished lens. This may be accomplished, for example, by usinga mold to produce a radius of curvature on the covering surface of thecovering layer equal to that of the front convex surface of the singlevision lens. However, it should be appreciated that even if a finishedsingle vision lens is used, the optical power may be changed if desiredby using a mold to produce a covering layer having a covering surfacewhich has a desired curvature different from that of the front convexsurface of the single vision lens.

As shown in FIG. 6, at step 700, a single vision base lens 800 can beselected, as further shown in FIG. 6A. At step 710, a recess 810 may becut into the front convex surface 804 of the single vision base lens 800shown in FIG. 6B. Alternatively, the single vision base lens 800 mayalready have a recess 810, such as may have been formed in the singlevision base lens 800 during its original manufacture. At step 720, anelectro-active element 200 and conductive bus 210 may be placed in therecess 810 as shown in FIG. 6C. At step 730, the electro-active element200 and bus 210 are conformally sealed using a resin-containing mold 820as shown in FIG. 6D. At step 740, the mold 820 is removed and a hardcoating may optionally be applied. In certain embodiments the hard coatis transferred from the mold during the conformal sealing. In this casethe inner concave surface of the mold used to produce the convexcovering surface 808 of the covering layer would have been pre-coatedwith a hard coat resin that is cured and transferred in the conformalsealing process. Because the single vision base lens described in thisexample may already be finished to have a desired fixed optical powerprior to conformal sealing, the inner surface of the mold 820 ispreferably concave with a radius of curvature equal to that of the frontconvex surface 804 of the single vision base lens 800. This yields aconvex covering surface 808 upon removal of the single vision base lens800 from the mold 820 after conformal sealing which is substantiallyidentical in curvature to that of the front convex surface 804, as shownin FIG. 6E, resulting in little to no change in the fixed optical powerof the single vision base lens 800.

Use of conformal sealing in the manufacture of an electro-active lenscan reduce the number of stock-keeping-units (SKUs) to 539, asignificant reduction compared to the number of SKUs commonly requiredfor conventional lenses.

To understand the significance of this improvement, one must understandthe number of traditional lens blanks needed to address mostprescriptions. About 95% of corrective prescriptions include a spherepower correction within a range of −6.00 diopters to +6.00 diopters, in0.25 diopter increments. Based on this range, there are about 49commonly prescribed sphere powers. Of those prescriptions that includean astigmatism correction, about 90% fall within the range of −4.00diopters to +4.00 diopters, in 0.25 diopter increments. Based on thisrange, there are about 33 commonly prescribed astigmatic (or cylinder)powers. Because astigmatism has an axis component, however, there areabout 180 degrees of astigmatic axis orientations, which are typicallyprescribed in 1 degree increments. Thus, there are 180 differentastigmatic axis prescriptions.

Moreover, many prescriptions include a bifocal component to correct forpresbyopia. Of those prescriptions that have a presbyopic correction,about 95% fall within the range of +1.00 to +3.00 diopters, in 0.25diopter increments, thereby resulting in about 9 commonly prescribedpresbyopic powers.

This results in the possibility of 2,619,540 (49×33×180×9) differentlens prescriptions, requiring a very large number of SKUs for a lensmanufacturer. This large number of SKUs is further increased due to thevariety of raw materials available for lens manufacturing as well asother special features available for inclusion in lens such asphotochromic tints. By providing most vision correctionelectro-actively, the number of SKUs is greatly reduced.

In another exemplary embodiment of the invention, the electro-activelens is manufactured by attaching two lens wafers together, with anelectro-active element sandwiched between the two lens wafers.

As shown in FIG. 7, at step 1000, a front and back lens wafer may beselected to have the desired optical characteristics for the fixeddistance refractive power to match a wearer's vision prescription. Asshown in FIG. 7A, a concave back lens wafer 900 and a convex front lenswafer 930 are selected. The front lens wafer 930 may have a radius ofcurvature of R1, while the back lens wafer 900 may have a radius ofcurvature R2. The fixed optical power of the lens wafers equals(n−1)×(1/R1−1/R2), where “n” equals the index of refraction of thematerial used to manufacture the lens wafers. Where both R1 and R2 areparallel to one another, the resulting base lens formed by attaching thelens wafers has a fixed optical power of zero.

As with other the electro-active lenses described herein, optical powerfor near and intermediate vision correction results from the addition ofthe fixed optical power, which typically provides optical power toprovide far distance vision correction, plus the optical power providedby viewing through an area of the electro-active lens containing theelectro-active element. It should be appreciated, however, that any lensmay be manufactured to have a fixed optical power which equals zero suchthat all vision correction is provided by viewing through the area ofthe electro-active lens containing the electro-active element. Likewise,viewing through the area of the lens containing the electro-activeelement may provide correction of non-conventional refractive error,including correction of higher order aberrations, for all focal lengths.

It should further be appreciated that through the use of customizedcasting, free-form manufacturing, or light initiated refractive indexchanges or light initiated refraction changes, it is possible to correctfor non-conventional refractive error using the base lens only or incombination with the electro-active element. In these embodiments, thebase lens may provide correction of non-conventional refractive errorindependent of the electro-active element, which may correct forspherical power adjustments or errors associated with conventionalrefractive error such as presbyopia.

Referring again to FIG. 7A, a recess may be cut into either one or bothof the surface opposite the convex surface of the front lens wafer 930and the surface opposite the concave side of the back lens wafer 900.Alternatively, a recess may already be present in the lens wafers 900,930, having been previously created, such as at the time of manufacture.FIG. 7A illustrates the front lens wafer 930 having a single recess 940in the surface opposite the convex surface of the front lens wafer 930.An electro-active element 910 and a flexible conductive bus 920 may beplaced between the back lens wafer 900 and the front lens wafer 930, theelectro-active element 910 and the flexible conductive bus 920 situatedto fit within the recess 940. As described in step 1030, the front lenswafer 930 and the back lens wafer 900 may be bonded together with anindex matched adhesive, to produce an electro-active lens.

In certain embodiments, the electro-active lens may be manufactured fromlaminated lens wafers, with the back lens wafer providing cylinder powerand the combination of the back and front lens wafers completing thesphere power of the lens.

It should be appreciated that in certain embodiments in the manufactureof an electro-active lens, step 1010 as shown in FIG. 7 is optional andno recess is required for the conductive bus and electro-active element.For example, in certain embodiments an electro-active element andconductive bus may be sandwiched between two lens wafers, whilemaintaining the proper relationship of the two wafers so as not tocreate a prismatic power unless it is desired to address the particularvision needs of the wearer. An index matched ophthalmic grade resin maybe applied between the layers and held in place by, way of example only,a peripheral gasket until cured, at which point the gasket could beremoved resulting in an electro-active lens.

In another exemplary embodiment of the invention, an electro-active lenscan be manufactured by molding the entire lens around an electro-activeelement, which is disposed in the bulk of the final electro-active lensproduct. FIG. 3 illustrates a top view of a semi-finished fly-away moldgasket 610 holding an electro-active element 200 and buses 410-413. Theelectro-active element 200 may be electrically connected to fourconductive buses 410, 411, 412, 413. The conductive buses 410, 411, 412,and 413 extend from the electro-active element 200 radially outward to amold gasket ring 420. FIG. 4 illustrates a cross-sectional view of thesemi-finished fly-away mold gasket of FIG. 3, including theelectro-active element 200 and the buses 410-413.

FIG. 5 illustrates a method of manufacture of electro-active lensesusing a fully molded semi-finished blank according to an embodiment ofthe invention. At step 500, a mold assembly which includes a top mold600 and a bottom mold 620, and a fly-away gasket 610 having a gasket topcavity 640, a gasket bottom cavity 650, an electro-active element and aconductive bus may be selected, as shown in FIG. 5A. At step 510, thegasket 610 may be placed on the bottom mold 620, as shown in FIG. 5B. Atstep 520, a resin 660 can be added to the mold assembly, which whencured, will form the lens. The resin passes into the gasket bottomcavity 650 through spaces between, or apertures in, the conductivebuses. It should also be appreciated that the mold assembly shown inFIG. 5D could be filled with a resin through a sealable aperture in theside of the gasket 610.

Ophthalmic grade resins such as those used in conformal sealing may beused. These resins include dietilenglycol bis allylcarbonate, such asCR39™ available from PPG Industries, Inc. of Pittsburgh Pa., high indexpolymers and other well known ophthalmic resin materials. At step 530,the top mold 600 may be positioned over the gasket top cavity 640, asshown in FIG. 5D. The resin between the top mold 600 and bottom mold 620is cured in step 540, as shown in FIG. 5E. At step 550, the top mold 600and bottom mold 620 may be removed along with the outer gasket ring 420,to produce a semi-finished electro-active lens blank, which may then besubjected to various finishing techniques to produce the finishedelectro-active lens.

It should be appreciated that while this embodiment describes themolding process in terms of cast molding, injection molding may also beused in the manufacture of an electro-active lens. In these embodiments,a material such as polycarbonate, for example, may be injection moldedinto a die and cured around an electro-active element and conductive buscontained within the die to manufacture an electro-active lens.

Various conductive bus arrangements may be used to manufacture theelectro-active lens of the exemplary embodiments of the invention.Typically, a bus or group of buses may be placed in any manner toconduct electricity radially outward from the electro-active element. Asshown in FIG. 8A, the electro-active element 200 may be electricallyconnected to a single conductive bus 1100. The bus 1100 extends radiallyoutward from the electro-active element 200. When the bus extendsoutward from the electro-active element it may also be utilized as anelectrical lead to connect a power source directly or indirectly to theelectro-active element 200.

In another embodiment, as shown in FIG. 8B, the electro-active element200 may be electrically connected to a plurality of conductive buses,such as conductive buses 1110, 1111, 1112. As with the single conductivebus of FIG. 7A, each of buses 1110, 1111, 1112 may be electricallyconnected at one end to the electro-active element 200 and may extendradially outward from the electro-active element 200. Preferably, eachof buses 1110, 1111, 1112 are spaced evenly around the electro-activeelement 200. It should be appreciated that any number of buses may bearranged to extend outward from the electro-active element 200 in a fullor partial wagon-wheel configuration. Increasing the number of busesincludes an advantage of providing a larger number of positions at whichelectronic components such as a rangefinder, controller, and powersupply may be placed to activate the electro-active element and provideelectro-active vision correction.

In yet another embodiment, as shown in FIG. 8C, the electro-activeelement 200 may be electrically connected to a disk shaped conductivebus 1120 that at least partially encircles the electro-active opticalelement 200. The conductive bus 1120 may comprise a plurality ofperforations or apertures 1125. These perforations 1125 may beadvantageous to allow resin to flow through and around the conductivebus 1120 lock the electro-active element 200 into the lens blank duringmanufacturing of the electro-active lens and may enhance bonding betweenthe conductive bus 1120 and lens wafers, if the electro-active lens ismanufactured with the use of lens wafers. The conductive bus 1120 iselectrically connected at the inner periphery of the disk to theelectro-active optical element 200.

FIG. 9A illustrates an electro-active lens 1200 having a conductive busarrangement connected to a rangefinder and controller. The conductivebus arrangement comprises an electro-active element 1205, anelectro-active substrate wafer 1210, an integratedcontroller/rangefinder 1220, a base lens 1230 and drive signal buses1240.

The rangefinder may comprise a transmitter and detector coupled to acontroller. In another embodiment, a single device can be fabricated toact in dual mode as both a transmitter and detector connected to thecontroller.

The controller may be a processor, microprocessor, integrated circuit,or chip that contains at least one memory component. The controllerstores information such as a vision prescription that may include thewearer's prescription for several different viewing distances. Thecontroller may be a component of, or integral with, the rangefinder. Itshould be appreciated, however, that the controller and rangefinder maybe separate components and need not be located at identical locations,only that the controller and rangefinder be electrically connected. Itshould also be appreciated that other view detectors, such as a microtilt switch to determine a wearer's head tilt or an eyetracker todetermine a wearer's line of vision could be used in lieu of, or incombination with, the rangefinder to determine what object a wearer isviewing and how the electro-active element should be activated toprovide a focal length corresponding to the object being viewed toprovide the wearer with proper vision correction.

The rangefinder is in electronic communication with the electro-activeelement, either directly or via the controller, through signalsdistributed through the conductive bus. When the rangefinder detectsthat the focal length produced by the electro-active element should beswitched to provide a different focal length, the rangefinder mayelectronically signal the controller. In response to this signal, thecontroller adjusts the voltage applied to the electro-active element toproduce a refractive index change that by itself, or in combination withother refractive index changes such as provided by the fixed opticalpower of the base lens will provide the desired vision correction. Thisrefractive index change may be used to correct for conventionalrefractive error, unconventional refractive error when the refractiveindex change is generated in a prescribed pattern using a pixilatedelectro-active element, or a combination of both conventional andnon-conventional error correction, either or both of which areconsistent with a vision prescription stored in the memory of thecontroller. The new index of refraction produces the appropriate opticalpower in the electro-active lens to correspond to the change in focallength.

In the case where non-conventional refractive error is corrected only bythe electro-active element and not through the use of free form lenstechniques, a pixilated electro-active element is used. Non-conventionalrefractive error may be corrected by applying a voltage to theelectro-active element, which creates a refractive index change to aplurality of pixels, contained within the electro-active element thuscreating a grid or pattern having a variety of indices of refractionwhich in combination provide for the correction of non-conventionalrefractive error.

The rangefinder may use various sources such as lasers, light emittingdiodes, radio-frequency waves, microwaves, or ultrasonic impulses tolocate the object and determine its distance. The light transmitter maybe a vertical cavity surface-emitting laser (VCSEL) is used as the lighttransmitter. The small size and flat profile of these devices make themattractive for this application. In another embodiment, an organic lightemitting diode, or OLED, is used as the light source for therangefinder. The advantage of this device is that OLEDs can often befabricated in a way that they are mostly transparent. Thus, an OLED maybe a preferable rangefinder to keep the lens aesthetically pleasing,since it could be incorporated into the lens or frames without beingnoticeable.

Referring to FIG. 9B, which is a cross-sectional view from the top ofthe lens shown in FIG. 9A, the controller/rangefinder 1220 may becontained within an electro-active substrate 1250 that may be furtherprocessed to produce an electro-active lens. Vias 1290 may be used toprovide electrical connection to circuitry buried in the base lens 1230.The outer surface of the base lens 1230 may then be coated withtransparent conductors 1293, 1296 which can be used to make electricalcontact with a positive and negative terminal of an external powersource, so that power can be applied to the electro-active element 1205and the controller/rangefinder 1220 by applying a potential across thetwo exterior surfaces of the lens.

The controller/rangefinder 1220 may be connected to the electro-activeelement 1205 by a series of conductive buses, such as in any of theconfigurations described herein. Preferably, the bus may be of a wagonwheel construction where the buses form spokes of the wheel, with theelectro-active element serving as the hub. The wagon wheel constructionprovides the option of the controller/rangefinder 1220 being mounted onthe lens 1200 in a number of different locations. Thecontroller/rangefinder 1220 may be connected at any point on anyconductive bus 1240 and is preferably at a periphery of the lens nearthe frame, or the controller/rangefinder 1220 alternatively may beattached to the frame, connected to the conductive bus 1240 via leads.This wagon-wheel conductive bus configuration also provides multiplelocations to apply a voltage across the electro-active element 1205 froma power source.

Alternatively, in certain embodiments an electrical conducting surfacemay be used as shown in FIG. 9C. In these embodiments a conductingpenetrating mechanism, such as a clamp having a first jaw 1282 and asecond jaw 1284 may be used, each jaw attached to opposite terminals ofa power source. The jaws 1282, 1284 may be tightened such that a portionof the jaws may penetrate the surface of the lens 1200 or otherwise makecontact with the surface of transparent conductors 1293, 1296 and thusconducting electrical power from the power source. In FIG. 9C, theconnective jaws 1282, 1284 are shown on opposite sides of the lens.However, it should be appreciated that both jaws 1282, 1284 maypenetrate the same side of the lens, provided that the proper insulationseparates the positive and negative leads.

In yet another embodiment of the invention, the contacts to a powersupply, such as a battery, may be mounted on or near a frame hinge 1305of a spectacle lens which may contain an electro-active lens 1200manufactured in accordance with the methods described herein. FIG. 10Aillustrates a rear view of a spectacles frame with the contacts to thepower supply mounted on or near the hinge of the frame according to anexemplary embodiment the invention. FIG. 10B illustrates a top view of aspectacles frame with the contacts to the battery mounted on or near theframe hinge according to an exemplary embodiment the invention. In someembodiments, the power supply, such as a battery 1320, may be connectedto the lens through the front of the lens by drilling holes 1330 to thepower terminals 1380, 1385 in the lens.

In some embodiments, the controller/rangefinder 1220 is mounted in thelens 1200 and the power to the controller/rangefinder 1220 and theelectro-active element 1205 is supplied by a battery 1320 attached tothe frame 1300. FIGS. 10A and 10B illustrate an embodiment in which thecontacts 1310 to the battery 1320 are mounted on or near the frame hinge1305, for example on the temple area of the frame. Alternatively, asshown in FIGS. 11A and 11B, the contacts 1310 to the battery 1320 canalso be made though the back of the lens 1200. The contacts 1310 may bemade from transparent, conductive materials such as ITO or otherconductive oxides or with a transparent conductive polymer.

FIGS. 12A and 12B illustrate an alternative embodiment of the contacts1310 to the battery 1320 mounted on or near the frame hinge 1305. Thecontacts 1310 may extend through the side of the frame 1300 into theside of the lens 1200. In such cases it may be advantageous to coat theouter edge of the lens 1200 with two conductive strips that areelectrically isolated from one another to impede the current beingsupplied to the device. These conductive strips may provide bettersurface contact and reduced impedance for the voltage being supplied tothe electro-active element 1205.

It is also possible to use a screw and frame hinge to mount an externalpower supply to the frame. In some embodiments the controller may alsobe mounted to the frame in this manner. FIGS. 13A-13D illustrate abattery attachment mounted on the frame hinge. The battery attachmentcomprises a battery 1320 with an attached support ring 1420, a framescrew 1410, and frame hinge 1305. The battery support ring 1420 may beinserted in the frame hinge 1305 to receive the screw 1410. The screw1410 may be inserted through the frame hinge 1305, which may be threadedto hold the screw 1410. FIG. 13D shows an alternative embodiment inwhich the battery attachment may further comprise a battery cradle 1322from which battery 1320 may be removed or replaced without disengagingthe screw 1410 from the battery support ring 1420.

The controller, rangefinder, and power supply of the electro-active lensmay be separate components placed on the lens or spectacle frame or theymay be integrated into a single module. FIG. 14 illustrates anintegrated battery, controller, and rangefinder which form a singlecontrol module for use in accordance with exemplary embodiments of theinvention. The control module may comprise, by way of example only, asemi-circular photo-detector 1700 and a semi-circular light emittingdiode 1710 which together form the rangefinder as a first component ofthe module. A controller 1720 may be positioned behind the rangefinderto form a second component, and a disk-shaped battery 1730 may be placedbehind the controller 1720. As shown in FIG. 15, these components form asingle control module 1810 which can be attached to the electro-activeelement 1830 via a conductive bus 1820 to provide power to theelectro-active element 1830 and to switch focal lengths of the lens 1800to provide the required vision correction for wearer of the lens.

FIG. 16 illustrates a method of finishing and mounting an integratedcontrol module into the lens. At step 1900, a layout may be selected fora desired spectacle frame taking into consideration the lens blank sizeand also the location of the wearer's pupils and the distance betweenthem. At step 1910, a lens blank 1975, which may typically be apreformed optic or semi-finished blank may be decentered based on thesize of the lens blank and the wearer's pupil alignment. In some cases,decentering may also be desired to produce a desired prismatic effect.The lens blank may also be rotated if an astigmatic correction isprovided by the non-electro-active portion of the lens. At step 1920,the lens blank 1975 may be surface cast or ground to provide a neededdistance prescription for the wearer. At step 1930, a recess may be cutor molded into the surface for receiving the electro-active element 1977and conductive bus 1979. It should be appreciated that step 1930 isoptional, and that a recess may previously have been created. At step1940 the electro-active element and conductive bus, as well as acontroller/rangefinder 1981 are inserted within the recess andconformally sealed to bury these components within the lens. The bus maypreferably be oriented in a location that the rangefinder and controllercan be placed near the edge of the spectacles frame, preferably near thetemple of a wearer.

However, it should be appreciated, that as with other embodiments, thecontroller and rangefinder need not be buried within the lens, but thateither one or both may later be added, such as by placement on aspectacles frame, or on the lens surface, and then electricallyconnected to the conductive bus contained within the lens. At step 1950the lens is edged into a shape for placement within a spectacles frameand then mounted within that frame. When edging the lens to the fit thespectacle frame, the lens should be edged to remove only those portionsof the lens which do not contain the electro-active element. Finally, atstep 1960 the battery is connected to the conductive bus. If thecontroller was not preprogrammed prior to installation, it may beprogrammed to contain information particular to the wearer, such as thewearer's vision prescription for different focal lengths.

Alternatively, any one or all of the rangefinder, controller, andbattery may be mounted on the spectacles frame and connected to theelectro-active lens through leads passing to the electro-active element.FIG. 17 illustrates a method of finishing and dispensing a lens with arangefinder, battery, and a controller in the spectacles frame. At step2000, a layout may be selected. At step 2010, a preformed optic or asemi-finished blank can be decentered and rotated as shown in FIG. 17 b.If the lens has a toric power and the electro-active element is placedover the optical center of the lens, the bus must be oriented relativeto the toric axis. At step 2020, the lens may be ground to a toric andsphere shape, as illustrated in FIG. 17C. The lens may be edged, as instep 2030, for placement in a spectacle frame shown in FIG. 17D. At step2040, the rangefinder, battery, and controller, shown as an integratedcontrol module 2060, may be mounted on the spectacles frame, to completethe process as shown in FIG. 17E. Alternatively, it should beappreciated that the integrated control module may be mounted on thespectacles frame during frame manufacture.

If required for the wearer's vision needs, prism may be added during thevarious embodiments of manufacturing an electro-active lens. Forexample, if a semi-finished blank is used, prism may be added andsurfaced into the lens as required by the vision prescription or in somecases the prism can be created by the decentration of the lens relativeto the wearer's inter-pupillary distance.

Similarly, other methods of modifying the electro-active lens duringmanufacture may be achieved such as by tinting the lens after surfacing,but preferably prior to hard coating. The lens can be also madephoto-chromic by conformally coating the lens with a photo-chromic layeror a material that is easily imbibed with a photo-chromic dye.Alternatively, the tint may be produced by an electro-chromic tintcreated by the electro-active element or by adding additional layers ofelectro-active material to the electro-active element.

An optional anti-reflective coating may applied to the lens, eitherbefore or after edging. To avoid out-gassing which may occur duringapplication of the anti-reflective coating, the electro-active elementshould be completely sealed within the lens.

The present invention is not to be limited in scope by the specificembodiments described herein. Indeed, various modifications of thepresent invention, in addition to those described herein, will beapparent to those of ordinary skill in the art from the foregoingdescription and accompanying drawings. Thus, such modifications areintended to fall within the scope of the following appended claims.Further, although the present invention has been described herein in thecontext of a particular implementation in a particular environment for aparticular purpose, those of ordinary skill in the art will recognizethat its usefulness is not limited thereto and that the presentinvention can be beneficially implemented in any number of environmentsfor any number of purposes. Accordingly, the claims set forth belowshould be construed in view of the full breath and spirit of the presentinvention as disclosed herein.

1. A method of manufacturing an electro-active lens comprising: coveringan exposed surface of the electro-active element to produce anelectro-active lens; wherein the exposed surface of the electro-activeelement is covered by a lens blank; and wherein the lens blank isselected from the group consisting of a semi-finished blank, anunfinished lens blank, a lens wafer, a preformed optic and a finishedlens blank; providing an electro-active element; wherein theelectro-active element is capable of focusing an image in ambient light;wherein the lens blank is a finished lens blank having an optical powerequal to a wearer's distance vision prescription; wherein theelectro-active element comprises a plurality of pixels.
 2. A method ofmanufacturing an electro-active lens comprising: covering an exposedsurface of the electro-active element to produce an electro-active lens;providing an electro-active element wherein the electro-active elementcomprises a plurality of pixels; where in the electro active elementprovides for a refractive change; wherein the refractive change correctsfor higher order aberration; wherein the electro-active lens is capableof focusing an image in ambient light.
 3. A method of manufacturing anelectro-active lens comprising: covering an exposed surface of theelectro-active element to produce an electro-active lens; wherein theexposed surface of the electro-active element is covered by a lensblank; and wherein the lens blank is selected from the group consistingof a semi-finished blank, and unfinished blank, a lens wafer, apreformed optic and a finished lens blank; providing an electro-activeelement; wherein the electro-active element comprises a plurality ofpixels; wherein the electro-active lens is capable of focusing on animage in ambient light; wherein the lens blank corrects a wearer'sconvention and non-conventional refractive error and wherein theelectro-active element corrects the wearer's spherical error.